Table 1.

Material and methods: screws below C1 placed in the lateral masses are in brackets

Case no.	Sex	Age	Diagnosis	Notes	C1 screws	C2 screws	C3–C4 screws	Fixation area	FU mos
1	F	62	Dens non-union	Collar failure	1	1	0	C1–C2	16
2	M	45	Dens non-union	Halo failure	2	2	0	C1–C2	25
3	F	18	Dens non-union	Halo failure	2	2	0	C1–C2	17
4	M	26	Dens non-union	Anterior screw failure	2	1 + (1)	0	C1–C2	17
5	M	58	Type II dens fracture	Halo refusal	2	2	0	C1–C2	21
6	F	31	Type II dens fracture	Irreducible	2	2	0	C1–C2	27
7	M	26	Type II dens fracture	T7 burst fracture	2	2	0	C1–C2	24
8	M	33	Type II dens fracture	C6–C7 dislocation	2	2	0	C1–C2	24
9	F	30	C2 body fracture	Unstable fracture	2	1	(2)	C1–C3	12
10	F	37	Hangman’s fracture	Anterior plate failure	2	0	(2)	C1–C3	19
11	M	40	C1–C2 instability	Os odontoideum	2	2	0	C1–C2	12
12	M	18	C2–C3 osteoblastoma	–	0	2	(3)	C2–C4	26
13	F	14	C2 osteoblastoma	Occipital paraesthesia	2	1	(2)	C1–C3	23
14	M	78	C2 chordoma	Previous vertebroplasty	2	0	(4)	C1–C4	13